"You’re trying to not think about it but it’s just constantly there. You can’t get rid of it.

"I was taking Ibuprofen and I was on the steroid cream, antihistamine tablets and literally for two or three days I was in excruciating agony, constantly being reminded of the pain until the blisters popped and started to heal up.

"The red marks, even after they’ve blistered the first time can last on your skin I’ve read online for up to four years.

"Some people have it up to six years and in extreme cases it can last up to 10 years."

Giant Hogweed or Heracleum mantegazzianum, is a weed which has dangerous effects on human health.

Growing up to five metres tall, its sap contains toxic chemicals which react with light when in contact with human skin, causing blistering within 48 hours.

Effectively it prevents the skin from protecting itself from sunlight, which can lead to very bad sunburn and scarring.

Exposure can result in blisters, long-lasting scars, and – if it comes in contact with eyes – blindness.